The 'S' stands for surprise

LA JOLLA, CA—Protein S, a well-known anticoagulant protein, keeps the blood flowing in more than one way, discovered researchers at the Salk Institute for Biological Studies. The protein contributes to the formation and function of healthy blood vessels.

The researchers found that mice lacking protein S suffered massive blood clots, but also had defective blood vessels that allow blood cells to leak into the surrounding tissue.